Grounding device



Nov. 3, 1942. I

0. J. GAUB 2,3005563 GROUNDING DEVICE.

Filed Oct. 29, 1941 Patented Nov. 3, 1942 l uN Eo" STATE T v, OFFICE 1GROUNDING DEVICE Otto J. Gaub, 01a Bridge, N. J. Application October 29,1941, Serial No. 417,006 (01. 173-273) 3 Claims.

such materials. Manygrounding devices for this purpose are available butin practical use have demonstrated several serious defects which reducetheir effectiveness and otherwise make them of doubtful utility. Forexample, in many such devices difliculty is experienced in attaching andremoving the clamp and this fault appreciably retards production.operations. Contact surfaces on previously available devices arearranged so as-to make electrical contact on the inside of the containerand thus become contaminated with the container contents, therebyreducing the effectiveness of the contact. Also, the contact surfaces onthe conventional clamp are fixed points andthesepoints soon become dulldue to the drag encountered in traveling over the edge of the containerwhen the device is attached and removed and this also reduces thecertainty of proper contact.

In the improved grounding device of the pres ent invention, these andother defects of previously available ground clamps are eliminated andits ready acceptance in the industry reflects the urgently neededadvantages offered in the new device.

This invention has as an object the provision of an improved portableground clamp which is simple in construction and which is readilyattachable and removable. Another object is the provision of a groundclamp which provides contacts outside the container to be grounded.Another object is the provision of an improved ground clamp in whichcontact is made by means of a rotatable element having sharp edges, thusinsuring more certain conduction of static charges. A further object isthe provision of an improved ground clamp in which contact is madethrough a roller construction, thus affording long life for the contactelement. A still further object is the provision of an improved groundclamp which hugs the side of the container due to the contact beingbelow the center of the rim or edge. A still further clamp which isparticularly adapted for use with I containers having a beaded ,topedge. Other objects will appear as the description of the inventionproceeds.

These objects are accomplished by means of animprovedground clamp whichcomprises essentiall y a rigid. non-sparking metal member offset inopposite directions to provide a hook at one end and a hand grip at theother and a non-sparking spring pressed roller grip element afiixed to,the rigid member and nested within the hook. 1

In the accompanying drawing which illustrates the. preferred embodimentof my invention: I

, Figure 1 is a sectional side view of the improved device showing thespecific arrangement of the various elements disposed in their properposition. 1

Figure 2 is a front .view of the device which illustrates theconstruction and position of the roller contact in relation to thesupporting element- V I Figure 3, shows thedetail of the roller contact.

Fig. 4 is a sectional side View of the device illustrating its utilityas a ground clamp for a container with a beaded top edge.

Referring specifically to the drawing: In Figure 1, the roller contact1, the rotatable shaft of which .is enclosed .by,t he turned end 2 ofthe spring supporting element 3 attached to the rigid metal member t byscrews 5, is nested within thehook 6. The spring supporting element 3preferably consists of two fiat flexible or semi-rigid membersadjacently disposed. The hook 6, which comprisesv an essential elementof the rigid member l, is-oifset in opposite direction to the hand gripI and preferably consists of a ghard portion 8, a stop 9 and a lip I0.The lip I0 also preferably terminates at a point directly opposite thecenter of the rotatable roller contact shaft. The lug II is attached tothe rigid element part of the device by the screws l2 and carries theground wire I3.

As previously stated, Figure 2 represents a front view of the devicewhich illustrates the disposition of the knife edge roller contact inrelation to the spring and contact holder. The identifying numeralscorrespond in their meaning tothose referred to above for Figure 1.

Figure 3 shows the detail construction of the knife edge roller contactcomprising two knife edge members fixed at opposite ends of arotatobject is the provision of an improved ground able shaft.

In Figure 4, the device is shown properly the clamp is difficult andsuch arrangement also causes undue flexing in the spring member. If thehook terminus is above the axis of the shaft of the roller contact,there is a tendency to force the clamp away from the container side andthus become loose or completely detached. l

The device is also preferably completely fabricated from a non-sparkingmetal such as beryllium, copper or bronze. Phosphor bronze issatisfactory for constructing the device and has been found to beparticularly adapted for the roller contact element and the springsupporting element.

In using the device, it is merely gripped by the hand grip l and pulleddown. over the rim of a container so that the hook terminus or lip l0engages the inside of the container. At the same time the knife edgeroller contacts in traveling over the edge of the outside of thecontainer cut through any coating or other non-conducting material onthe outside surface of the container, thus insuring positive contactwith the metal of the container, To remove the device it is onlynecessary to lift up with slight pressure on the hand grip.

The improved ground clamp is useful generally for grounding staticelectricity, particularly for grounding metal containers which containinflammable materials. It is especially adapted for containers whichhave a beaded top edge.

The advantages of the new grounding device are several and commerciallyimportant as refiected by the immediate and rapidly growing acceptancein the industry. The device is simple in construction and in use is morereadily attached and removed than in such devices heretofore available.Contacts are outside the con tainer rather than on the inside asprovided by older ground clamps and this is important in containers forpaint materials where contamination of contact points and resultantuncertain contact is obviated. The device provides sharp knife edgerotatable contacts, thus insuring more certain contact and conduction ofstatic charges. The roller construction of the knife edge contactsaffords long life for the contact element. The preferred embodiment ofthe invention which provides contact below the center of the rim or edgeof the container causes the device to hug the side of the container andprevents accidental loosening or dislodgement of the device. The newclamp is of particular advantage for grounding containers which have abeaded top edge, a type of container for which grounding devicesheretofore available have not been satisfactory,

It is apparent that many widely different embodiments of the inventionmay be made without departing from the spirit and scope thereof; and,therefore, it is not intended to be limited except as indicated in theappended claims.

'I claim:

1. A portable non-sparking metal ground clamp, particularly adapted foruse with containers having a beaded top edge, comprising a rigid metalmember with a hook at one end and a hand grip ofiset in oppositedirection at the other end and a springpressed roller grip elementafiixed to the rigid member and nested within the hook, said roller gripelement consisting of a rotatable shaft carrying knife edge circularcontact members at each end of the shaft and mounted at the free end ofthe spring element.

2. A portable non-sparking metal ground clamp, particularly adapted foruse with containers having a beaded top edge, comprising a rigid metalmember with a hook at one end and a hand grip offset in oppositedirection at the other end and a. spring pressed roller grip elementafiixed to the rigid member and nested withinthe hook, said roller gripelement consisting of a rotatable shaft carrying knife edge circularcontact members at each end of the shaft and mounted at the free end ofthe said spring element so that the axis of the rotatable shaft isdisposed directly opposite the end of the hook.

3. A portable non-sparking metal ground clamp, particularly adapted foruse with containers having a beaded top edge, comprising a rigid metalmember with a hook at one end and a hand grip offset in oppositedirection at the other end and a phosphor bronze spring pressed rollergrip element afiixed to the rigid member and nested within the hook,said roller grip element consisting of a rotatable shaft carrying knifeedge circular contact members at each end of the shaft and mounted atthe free end of the spring element.

OTTO J. GAUB.

